Optimized Riemann Solver to Compute the Drift-Flux Model

Abstract

This paper discusses the development of an approximated optimized Riemann solver applied to the two-phase flow drift-flux model. The solver makes use of a partial eigenstructure information while maintaining the Roe solver accuracy. Moreover, it allows to take into account the contribution of the dynamic and thermal non-equilibrium in the upwinding matrix. A further optimization of the solver is realized by scaling the global matrix which results in better preconditioning. Both the partial eigenstructure decomposition and the scaling of the matrix are inspired from the eigenstructure of the two-phase flow model. A number of physical benchmarks are presented to illustrate this method. Comparison between the computational results obtained with the optimized solver and the conventional Roe-type solver demonstrates the efficiency of the new methodology. © Springer-Verlag Berlin Heidelberg 2011.